Give the gift of Retro Gaming with the $50 Raspberry Pi

I built a retro gaming console with the Raspberry Pi recently for my 7 year old son and he really liked it. Not only is it great revisiting all those old favorite games but with a few tweaks he can use it independently. There was a lot of things I had to figure out myself and I figured there may be a few other dads out there trying to same thing so I put all the information in this comprehensive guide. Feel free to comment on any part that is wrong or unclear.